Control of pyrolytic conversion



Jan. 17, 1928. 1,656,724

J. R. CARRINGER CONTROL OF PYEOLYTIC CONVERSION Filed May 28. 1923 avwemtoz a5; ui aw sy Patented Jan. 17, 1928.

UNITED STATES PATENT OFFICE.

JAMES RAYMOND OARRIN GER, OF HILLSIDE, NEW JERSEY, ASSIGNOR TO STANDARD OIL DEVELOPMENT COMPANY, A CORPORATION OF DELAWARE.

CONTROL OF PYROLYTIC CONVERSION.

Application filed Bay 28,

This invention relates to the art of pyrolytic conversion of hydrocarbons and will be fully understood from the following description, reference being had also to the accompanying drawing which represents/semi-diagrammatically a form of apparatus contemplated in the invention.

In the drawing the reference character A designates a heating coil or conduit, made up, for instance, of parallel tubes 1 connected at their ends by suitable cross-over connections from tube to tube and from row to row to form a consecutive path, and mounted in a suitable furnace 2. From the heating conduit a connecting line 3 leads off to the cracking or digesting passageway D. In the illustration this cracking or digesting passageway is made up of an elongated drum suit-ably guarded against heat loss as by a lagging of heat insulation C, or instead of this, the drum may be mounted in a flue to be bathed in waste flue-gases Where desired, the feature in any case being that loss of heat from the drum contents is provided against. Connected in the pipe or line 3 from the heating conduit A to the digesting passageway D is a suitable regulator or cooler tower B comprising a shell i'forming a container about the pipe coil 5 and having at its upper end outlets for air and at its lower end inlets with adjustable dampers 6. A by-pass line 7 with a controlling valve is provided connecting around the structure just described.

From the digesting passageway D a pipe 10 leads through a pressure control valve.

11 to a suitable vapor separator S. A vapor off-take 12 at the top of the vapor separator leads to a suitable condenser and receiver, not shown, and a tar line 13 is provided at the bottom for withdrawal of residuum.

Assuming oil to be cracked entering the system by the pipe 14, being forwarded by a suitable pump, on traversing the heating conduit A the temperature is raised to incipient cracking and the discharged stream proceeds on to the digesting or cracking passageway D where it is allowed to crack to the desired extent While relatively slowly passing through this digesting zone, conversion going torward on the acquired heat. r, geferably, a considerable portion of the crac 'ng may be accomplished in the heating conduit and the process then be finished in the passeway D, In order to maintain 1923. Serial No. 641,895.

a high efiiciency in the furnace of the heating conduit, temperatures are liable to be reached at the coil outlet which may be higher than the temperature most desirable in the digesting zone D. In such case the temperature of the stream discharged from the heating conduit may be reduced to the point desired, before entering the drum D, by the cooler B. For this purpose suitable regulation of dampers 6 allows flow of air up through the shell 4 over the pipes 5, resulting in a cooling effect. The by-pass pipe 7 may also be brought into use, if desired, suitable regulation of the valves 8 and 9 allowing as muchor as little of the hot stream from the heating conduit A to be exposed in the cooling zone B as desired, preparatory to entry into the digesting or cracking zone D. p

The amount of surface exposed in the cooler B may be widely varied in accordance with the amount of ipe assembled and exposed in the coil 5, and in general will be based upon the particular needs of the plant.

In some cases I contemplate substituting for the air inlets and outlets in the shell 4, pipe inlet and outlet connections for passage cooling fluid other than air, for example,- water, oil or steam, and in any case it will be understood that the feature is the provision of a cooling medium about the walls of the pipe conducting the hot products from the heating conduit to the digesting passageway, such cooling means being usable when and to the extent desired.

Although I have described the invention by reference to specific details, it will be understood that chan es may be made which come within the spirit and scope of the invention.

What I claim is:

1. In apparatus of the character described, the combination of a heating conduit, a digesting or cracking passageway having provision against material temperature loss, a connecting line from said heatingconduit to the digesting passageway, an air-cooled tower on said connecting line, dampers for regulating the air flow in said tower, and

a vapor separator for receiving products from the digesting passageway.

2. Ilhe improvement in the art of pyrolytic conversionof hydrocarbons which comprises flowing a stream of the h drocarbons through a heating zone raising t e tempera.- ture to crachng range, flowing said hydrocarbons through a temperature limiting zone for controlling against undesired high tem Eeratures of the hydrocarbons by indirect eat exchange with a cooler fluid, and flowing said partially cooled hydrocarbon's to a digesting zone for further cracking.

3. In the art of pyrolytic conversion of hydrocarbons in which the hydrocarbons are passed through a heating zone and then through a digesting zone, the improvement which comprises flowing a stream of hydrocarbons through a heating zone, raising the temperature to cracking range, flowing said heated hydrocarbons through a zone wherein 

